Quality Function Deployment and Specifications

Transcription

1 Quality Function Deployment and Specifications Christopher Saldana, Ph.D. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta, Georgia, USA

2 Learning Objectives Identify types of customers Identify and interpret customer needs Define engineering requirements Translate customer needs to engineering requirements using a house of quality (HOQ) Use a HOQ to show relationships among customer needs and engineering requirements Create a specifications list from engineering requirements and customer needs 2 2

3 Who is the Customer for this System? airlines passengers flight attendants pilots ground crew TSA air traffic control FAA and many others. 3

4 Three Types of Quality/Features Basic: Expected of assumed Typical of invisible products Functions of products Performance: One dimensional Most market research Excitement: Pleasant surprises or customer delights Unexpected 4 4

5 Customer needs are found by asking, observing, and testing Focus Groups One-on-One Interviews Lead Users Articulated Use Interviews Ethnography Empathic design Many others... Lin, J., and Seepersad, C., 2007, Empathic Lead Users: The Effects of Ex- traordinary User Experiences on Customer Needs Analysis and Product Rede- sign, ASME DETC Design Theory and Methodology Conference, Las Vegas, NV, ASME, New York, Paper No. DETC

6 Customer needs are specific, positive, and solution-neutral (ish) MIT OpenCourseWare: Thomas A. Roemer 8

7 Customer Needs (e.g., Page Turner) Question Customer Statement Interpreted Need Importance Typical uses Independent use by student Operable by person with (must) 4 disabilities Likes Portable, Mobile Auditory sound provided when page is turned Adjustable stand for different book sizes Portable Signals when performing desired actions Adjusts to different book sizes (good) 3 Dislikes Suggested Improvements Used so much that we wore it out Heavy Need consistent page turning Built in delay for multiple button pushes Be able to turn newspaper pages Be able to turn scrapbook pages Multiple students can share Lightweight Repairable by staff Easily replaceable parts Predictable page turning Low failure rate Long mean time between failures Turns variety of page types Accounts for accidental, repeat button pushes Operable by multiple persons (good) 3 (good) 3 (must) 4 (must) 4 (should) 2 (should) 2 (good) 3 (must) 4 9

8 Linking Customer Needs to Specifications Engineering Requirements and Specifications Translate Voice of the Customer to Technology 10

9 Quality Function Deployment (QFD) QFD is a design planning tool: for translating customer needs into appropriate product development requirements that identifies the significant item on which to focus time, product improvement efforts and other resources QFD enables: the identification of important issues and items the identification of trade-offs and synergies Customer Supplier Customer Supplier QFD 11

10 Effect of QFD on Performance Changes = Money Earlier Changes = Less Money Spent HOQ Images from: Hauser, J.R., and D. Clausing, The House of Quality, Harvard Business Review, May/June 1988, pp

11 House of Quality (HOQ) Design tool for coordinating design efforts towards goods customers WANT House of quality (HOQ) is part of QFD Focus on quality and customer needs across the design process and across corporate boundaries Guide design priorities based on customer needs and competitive benchmarking Over 70% of US companies use QFD (Ford, Xerox, Toyota ) 13

12 House of Quality (HOQ) HOQ Translates Needs to Specifications Customer desires (qualitative) Not tied to product/concept Example: portable Customer Needs HOQ Engineering Requirements and Specifications Product performance (quantitative) ~Not tied to product solutions TESTABLE NOT A TEST Specification is a: Metric with Target Value & units mass < 0.1 kg volume < 250 cm 3 Revised throughout design 14

13 House of Quality (HOQ) components Customer needs Engineering metrics/requirements Targets Direction of improvement Conflict/synergies Relationship matrix Correlation matrix Alternative products (1) LEFT Weighted Customer Needs (6) TOP Conflicts & Synergies direction of improvement (3) CEILING Metrics (for customer need fulfillment) (4) CENTER Metrics vs. Customer Needs (relationships) (5) BOTTOM Metric Targets (engineering specification targets) (2) RIGHT Customer Perceptions (of products & concepts) 15

14 House of Quality (HOQ) components Customer needs: These are the whats Assigned numerical importance 1-10 Engineering metrics/requirements: These are the hows Determine most important ones using RM Determine synergies/conflicts with CM Relationship matrix (RM): Maps relationship between hows and whats Quantitative relationship levels - 1, 3 and 9 Correlation matrix (CM): Maps correlation between engineering requirements Strong positive, positive, negative, strong negative 16 16

15 Relationship Matrix in HOQ Customer Requirements (Explicit and Implicit) Direction of Improvement Engineering Requirements operable by person with disabilities Portable/Mobile Signals when performing desired actions lightweight repairable by staff easily replaceable parts predictable page turning low failure rate safely handles variety of reading materials tolerance of user-initated motions grip force required of operator total mass carrying dimensions auditory volume of signals match signals with user generated action intensity of visual signals number of assembly and disassembly orie error in aligning parts # specialty components # tools needed to repair granularity of page turning control error rate in page turning rate of wear of components adjustable range of dimensions force on the page 17

16 Correlation Matrix in HOQ tolerance of user-initated motions grip force required of operator total mass carrying dimensions auditory volume of signals match signals with user generated actions intensity of visual signals mber of assembly and disassembly orientati error in aligning parts # specialty components # tools needed to repair granularity of page turning control error rate in page turning rate of wear of components + adjustable range of dimensions force on the page Column # tolerance of user-initated mo grip force required of operato total mass carrying dimensions auditory volume of signals match signals with user gene intensity of visual signals number of assembly and disa error in aligning parts # specialty components # tools needed to repair granularity of page turning c error rate in page turning rate of wear of components adjustable range of dimensio force on the page 18

17 Target Values for Engineering Requirements Determine how specific values for engineering requirements influence satisfaction of customer needs Coffee grounds example Scientific studies Survey tests Focus groups Refer to standards organizations (NIOSH, OSHA, NIST, ASTM, etc) 19 19

18 HOQ Example (e.g., Coffee) What Hot Taste Smell Stimulating Aesthetics Color Cost Grounds Not poisonous (assumed) How Serving temperature (Hot) Taste jury (Taste) Smell jury (Smell) Measure caffeine level (Stimulating) Jury (Aesthetics) Color standard (Color) Price (Cost) Filter & weigh (Grounds) Lethal Dose LD 50 (Not poisonous) 20

19 Cup of Coffee House of Quality (Filled) Matrix Weights Strong, = 9 Medium, = 3 Weak, = 1 The 181 from column 1 comes from: The sum of the Absolute Importance row is: = 682 The 0.27 in the first column of the Relative Importance row comes from: = »

20 Analyzing and Diagnosing the HOQ Look for: Blank rows unaddressed customer need Blank columns unimportant engineering requirement Communication opportunities Sales Points competitors strengths/features Resolve or prioritize negative correlations Final correct targets Determining planned quality What design requirements to be deployed to Phase II (Parts Deployment) 22

21 4 Phases of QFD Product planning What will it do? What will it look like? Part deployment How will it do it? Process planning How will we make it? Production planning Develop details in how to make it

22 4 Phases of QFD (e.g., Car Door) Product planning Close door easily Close fit Part deployment Weather strip Latch Process planning (W. Strip) Extrude Production planning Temperature Pressure Speed 24 24

23 Summary QFD/HOQ Customer requirements Rank based on customer priority Engineering requirements Must be measureable (e.g., engineering units), have improvement direction and a target value Rate relationship to customer requirements Relate tradeoffs with other engineering reqs. Determine most important ones using calculation Describing this figure in text Describe chart s contents, not what the chart is itself! What is important for each set of data? Use numerical information from figure See Ch. 2 in book for detail, templates online 25

24 Specifications: metrics lead to solutions /Homework/W12/ME480HWTwoSols.ht ml 26

25 Linking Customer Needs to Specifications Engineering Requirements and Specifications Translate Voice of the Customer to Technology 27

26 Specification List Specifications: Performance/engineering requirements that product must meet or exceed. Specifications sheet: Indicates changes to engineering requirements Indicates importance of the engineering requirement (demand or wish) Provides a quantifiable requirement (unit and value, or standard) Assigns responsibility Provides source justification (standard, calculation, report, survey, etc.) Connection to HOQ / QFD 28

27 Specification List D = Demand W = Wish Specification Issued: for: Page 1 Changes D/W Requirements Resp. Source Replaces issue of 29

28 Specification List Checklist Geometry Size, height, breadth, length, diameter, space requirement, number, arrangement, connection extension Kinematics Type of motion, direction of motion, velocity, acceleration Forces Direction of force, magnitude of force, frequency, weight, load, deformation, stiffness, elasticity, stability, resonance Energy Output, efficiency, loss, friction, ventilation, state, pressure, temperature, heating, cooling, supply, storage, capacity, conversion 30

29 Specification List Checklist Material Physical and chemical properties of the initial and final product, auxiliary material, prescribed materials (food regulations, etc.) Signals Inputs and outputs, form, display, control equipment Safety Direct safety principles, protective systems, operational, operator and environmental safety Ergonomics Person-machine relationship, type of operation, cleanliness of layout, lighting, aesthetics Production Factory limitations, maximum possible dimensions, preferred production methods, means of production, achievable quality and tolerance 31

30 Specification List Checklist Quality control Possibilities of testing and measuring, application of special regulations and standards Assembly Special regulations, installation, siting, foundations Transport Limitations due to lifting gear, clearance, means of transport (height and weight), nature and conditions of dispatch Operation Quietness, wear, special uses, marketing area, destination (for example, sulphurous atmosphere, tropical conditions) 32

31 Specification List Checklist Maintenance Servicing intervals (if any), inspection, exchange and repair, painting, cleaning Recycling Reuse, reprocessing, waste disposal, storage Costs Maximum permissible manufacturing costs, cost of tooling, investment and depreciation Schedules End date of development, project planning and control, delivery date 33

32 Automated Page Turner Example Requirement Target Value Resp. Test Source Geometry Forces Range of book heights 3-12 in Donnell Measurements; book sample studies Range of book thicknesses in Donnell Measurements; book sample studies Range of book widths 5-10 in Donnell Measurements; book sample studies Shear force on the page < 40g/m 2 Telenko calculation; book sample studies Book study [1] Book study [1] Book study [1] TAPPI Newspap er [2] 34

33 35 Coffee Example Entries in Houses of Quality From QFD Deployment are Sources Of Specifications House Of House Of House Of House Of House Of Quality #1 Quality #1 Quality #2 Quality #3 Quality #4 What How / What (#2) How / What (#3) How / What (#4) How Cust. Req. Characteristic Feature Process Production Hot Serving Temp. Water Temp. Water Speed Thermometer Smells Good Smell Jury Bean s Origin Heater Output Flow Control Tastes Good Taste Jury Water Quality Brew Time Timer Cheap Price Weight/Serving Brew Temp. Cleaning Plan Good Color Color Std. Fineness Of Ground. Grind Setting Non-Poisonous Analysis Age Of Coffee Water Source No Grounds Filter/Weigh (Raw, Brewed) Filter Quality Time To Serving Reinitialize (Renew Filter, Grounds) Disposal Plan (Raw, Brewed) 35

34 Coffee Specifications #1 Specification Issued: For: CUP OF COFFEE Page 1 Changes D/W Requirements Resp. Source Cup Of Coffee Energy Hot Material Good Color Non-Poisonous No Grounds Safety Non-Poisonous Signals Good Color Smells Good Tastes Good Costs Cheap Quality Control Good Color Smells Good Tastes Good 1st HoQ WHATs from class Replaces Issue Of 36

35 Next Level Of Detail In Specs... House Of House Of House Of House Of House Of Quality #1 Quality #1 Quality #2 Quality #3 Quality #4 What How / What (#2) How / What (#3) How / What (#4) How Cust. Req. Characteristic Feature Process Production Hot Serving Temp. Water Temp. Water Speed Thermometer Smells Good Smell Jury Bean s Origin Heater Output Flow Control Tastes Good Taste Jury Water Quality Brew Time Timer Cheap Price Weight/Serving Brew Temp. Cleaning Plan Good Color Color Std. Fineness Of Ground. Grind Setting Non-Poisonous Analysis Age Of Coffee Water Source No Grounds Filter/Weigh (Raw, Brewed) Filter Quality Time To Serving Reinitialize (Renew Filter, Grounds) Disposal Plan (Raw, Brewed) 37

36 Coffee Specifications #2: Hows? Specification Issued: for: Cup Of Coffee Page 1 Changes D/W Requirements Resp. Source Cup Of Coffee 10/3/95 10/3/95 10/3/95 10/3/95 10/3/95 Energy: Serving Temperature Material: Color Std Non-Poisonous Brewed Coffee Should Yield Minimum Coffee Grounds When Filtered Safety: Non-Poisonous Signals: Color Std Smells Jury Taste Jury Costs: Minimize Price Quality Control: Color Std Smells Jury Taste Jury Replaces issue of 1st HoQ from class NIST STD FDA 1st HoQ from class FDA NIST STD 1st HoQ from class 1st HoQ from class NIST STD 1st HoQ from class 38

37 Coffee Specifications #3: How Much? 39

38 Continue with Next Level of Detail in Specs House Of House Of House Of House Of House Of Quality #1 Quality #1 Quality #2 Quality #3 Quality #4 What How / What (#2) How / What (#3) How / What (#4) How Cust. Req. Characteristic Feature Process Production Hot Serving Temp. Water Temp. Water Speed Thermometer Smells Good Smell Jury Bean s Origin Heater Output Flow Control Tastes Good Taste Jury Water Quality Brew Time Timer Cheap Price Weight/Serving Brew Temp. Cleaning Plan Good Color Color Std. Fineness Of Ground. Grind Setting Non-Poisonous Analysis Age Of Coffee Water Source No Grounds Filter/Weigh (Raw, Brewed) Filter Quality TIME TO SERVING REINITIALIZE (RENEW FILTER, GROUNDS) Disposal Plan (Raw, Brewed) 40

39 Summary Specification Sheet Elements List engineering requirements from HOQ Add other specifications that are useful Make sure specifications can be measured Do not specify specifications dependent on design decisions, design choices come later! Describing this figure in text Describe the contents, not the tool itself! What are critical specifications? Use numerical information from figure. See Ch. 4 in book for detail, templates online 41

40 Learning Objectives Identify types of customers Identify and interpret customer needs Define engineering requirements Translate customer needs to engineering requirements using a house of quality (HOQ) Use a HOQ to show relationships among customer needs and engineering requirements Create a specifications list from engineering requirements and customer needs 42 42